I use Isabelle, Yoshi bike, azure rollers and gold glider. Is this combo any good for 200cc, and if not, how can I improve it? (I would prefer to have inside drifting)

It all comes down to personal preference. If your combo feels right for you, then use it.

You can always take a look at what the top runners use as a setup. Not sure if any one them use inward though

@SnipinG117 AeonFrodo uses inward bikes to my knowledge.

In my research, I found (using https://www.mk8dxbuilder.com/ this website) that my kart is pretty similar statwise to other people highly ranked in 48 tracks 200cc no items, so I guess the only difference is inside versus outside drifting.